Duloxetine for pain in Parkinsons disease

Abstract

© 2020 Shahrul Azmin Bin Md. RaniPain in Parkinsons disease is common and poorly managed. The body of literature showing that pain adversely impacts on the quality of life of Parkinsons disease patients is overwhelming. Different strategies have been adopted to address pain in Parkinsons disease but results have been mixed. The pathophysiology of pain in Parkinsons disease is thought to involve dopaminergic and extra-dopaminergic factors. Duloxetine, a serotonin and noradrenaline reuptake inhibitor has been used for pain in multiple sclerosis and painful diabetic peripheral neuropathy. We embarked on a project to explore the role of duloxetine in Parkinsons disease patients with pain in a randomized double blind placebo controlled trial using validated pain questionnaires, pain sensitivity measurements and functional imaging techniques. We showed a statistically significant improvement in the pain scores of the affective component of the Short-Form McGill Questionnaire and a trend towards improvement in pain tolerance following evoked pressure stimulus in the duloxetine group as compared to the placebo group. Additionally, the changes were not associated with changes in the affective states of the participants, as measured by the Geriatric Depression Scale and Positive Affect and Negative Affect Schedule. We did not find any statistically significant difference in the task-based fMRI and the resting state fMRI between the groups. In conclusion, our study showed that duloxetine may be most effective in addressing symptoms arising from the affective dimension of pain in Parkinsons disease patients